Ignition-coil.



E. EISEMANN.

IGNITION COIL. APPLICATION FILED Nov.9',1911.

1,108,892. Patented sept.1,1914.

T GRD UND TD DISTH/BUTER AND SPARK PLUG To BATTERYAND gnou/vn [/0 UNITED STATES PATENT OFFICE.

ERNST EISEMANN, 0F STUTTGART, GERMANY.

IGNITION-corn.

Specication of Letterslatent.

Application filed November 9, 1911.

Patented Sept. 1, 1914:. serial no. 659,409.

nition-Coils, of which the following is ay specification.

This invention relates'to ignition coils for battery' or double ignition. l

W'hether it is solely a matter of the ignition of an internal combustion motor by means of the same, or of an auxiliary igni-` tion in the case of so-called double ignition,

Vthe disadvantages of battery ignition are due, on the one hand, to the diminution of the strength of the spark as the speed of the motor increases, caused by the impedance of the coil, and, on the other hand, to the'strength of the spark not being able to be increased in any way by increasing the battery voltage, the platinum contacts of the trembler being thereby subjected to very rapid wear. v

A primary object of my invention isto obviate these defects.

The invention substantially consists Iin connecting in series with the primary winding of the coil a resistance which, when the speed of the motor is low and the successive breaks follow one another correspondingly slowly, allows only a certain maximum current to flow through the primary winding inconsequence of the ohmic resistance of the resistance and the fall in tension -brought about by it. When the speed rises, however, and the strength of currentdiminishes in consequence of the impedance of the resistance coil being increased owing to the rapid successions of breaks, the ohmic drop also .decreases in ratio so that the voltage available at the terminals of theV primary winding is correspondingly greater.

By correctly proportioning the prima-ry Winding of the ignition coil and the resistance coil I can provideithat the inductive action of the ignition coil remains approximately constant at the lowest and highest speed, and consequently that the sparks remain nearly equally powerful independently of the speed.

For a more detailed understanding of the invention, reference is to be had to the following description and appended claims,

taken in connection with the accompanying.

drawings, in which the figure is a central `vertical section of the device with the wiring Shown diagrammatically.

The apparatus is in the form of a unitary structure which can be mounted at any suitable point on the automobile or engine with which it is to be used. The device comprises a casing a of insulatin material which is @provided with a metallic ring d on which is fastened a cap c. VVithinthe casing a 1s a. magnetic core o on which are primary `and secondary windings A and C, the first Winding consisting of a few turns of coarse wire and the latter of many lturns of fine Wire. In the lower end of the casing is a disklor plate 5 of insulating material which carries the binding posts t and r, the former of which forms a common terminal for the lower ends of both the primary and Secondary windings, While the latter forms the terminal for the upper end of the secondary winding The core 4 has its lower end fitted in a metallic cup 8 which is partially .countersunk or set into the disk, 5 and is held in place by a bolt u which is screwed intothe cup, and its upper yend fits into a cup m on the lower face of the plate n. The said bolt is anchored or otherwise fastened in the disk 5 and extends centrally through the spoollike core or support 10 formed on the bottom of the lower cap 11 for the casing a, which cap tsaround the portion of the disk 5 that extends out of the casing. On vthe lower end of the bolt 9 is a nut 12 for'retaining-the cap 11 in place, and coperating with the 11111212 is another nut o to term a binding post to which they ground Wire 14 of the condenser Z is connected. Surrounding the portionl() ofthe cap 11 is a resistance B which has one end `connection by a Wire 16 to the binding post t, and the other end connected by a wire -17 with a source of current such as a battery which is in turn connected with ground.

In the upper end ofthe casing a is a chambercd metallic body or holder z' which contains a condenser l, the terminal 22 of which is connected with the bottom or inner plate n of the/condenser holder, While the other terminal 24 is connected with a Wire 25 leading from the interrupter contact f. The bottom plate n of the condenser holder has a socket m for receiving the the holder z" and insulated therefrom 1s a fined contact 28 to Which the upper terminal of the primary Winding is connected by a Wire 29, and coperating with this contact is a spring contact 7c Which is fastened to the post 3l, also on top of' the'holder. For permitting the contacts 28 andv 71: to be engaged and' disengaged, when 4it is desired to use or cut out the same, the cap c is rotatably mounted on the ring d, being connected thereto by'a bayonet joint. hastened to the cap o is an operating handle b and 'a screw h passing through the cap is adapted to yengage a stop 36 on the condenser holder 20 so as to limit the movement of the cap when the insulating projection g causes the lcontact 7: to engage the contact 28. make and break device D is used in connection WithV the contacts 28 and 30 for the starting by the battery or primary current.'

lfrom the foregoing it vvill be understood that current is brought'from.` a battery by the Wires 17 and that one pole of saidbattery or. othersource of current 'is grounded. 'lhe -Wire 17 is connected toa ringe@ yfrom* which the current passes to the resistance,

:coil B into the ring t1. The rin .4:1 is connected by a Wire lbto the bin ingpost t which forms one terminal of both the primary and secondary coils A .and G,- respectively. lfrom the binding post 't the current passes through the'primary coils A to the,

conductor 29 `which leads to the post 28,.

From the post Qicurrent passes into the lsvvitch arm cvvhenever the cap cis in lsuch position that the insulated member g holds the member in contact *with4 the `post 28. llrom the member 7c the primary current for attery current passes into the conductor 38 which `connects with the interrupter D. ANew the interrupter Dcomprises a pivoted arm e which is operated in one direction by a spring so that it will contact withy themaryl current. Hows through' the conductor 25 to ground and thence to the negative side of the battery, or other source of current. It will be seen, moreover, that the condenser Z is connected across the interrupter D, there being a conductor 24 connected to the conductor 25 and to one side of said condenser, While the other side of said conductor-is connected to the post 22 from Licencia which point electrical connection is made through the dislr a, core c, bolt u, contact c and conductor lelto ground. 'ihesecondary circuit leads from the binding pest tthrough the secondary coil D, thence to the binding post r and thence to the conductor l2 which leads to the distributer and spark plug, one side of whichv latter element is always grounded. From the grounded side of the spark plug the secondary' circuit is com- 'pletec through the battery and coil D to the post t, and also through the interrupter D and primary coil A to the same point whenever the member e is in contact with lt will be understood further that 1V prefer to drive the revolublefmember e of the interrupter D from the engine by means of a gear mechanism whichv Will permit me to rotate saidy member c by hand when the engine is stopped. This is for-the purpose of obtaining a sparlr rfrom the previously described. apparatue when the engine -is stopped in order to ignite a charge 'of gas `which may be held in one of the engine cyl# inders and thus start the; engine-Witheet vcranlning.v .Hovveven itvvill be understood that such gear mechanism is Well lmown in the art of ignition, having been commonly used fordriving magneto generators, and conse uently l do not deem it necessary to descri e such mechanism `in the-'present aplplication and do ynot 'lay claimlto the same in combination'rvith any other features of the device shown and described herein.'

-By suitably. propestinning` the relation 'of the primary Winding ttofthe external resistan'ce B, it is' possible to hold'the'inductiveaction. of the spark coil appron'lmately constant both at the lowest and. highest speeds of theimoton' .As a result, the'ignition spark vvillibe'of approximately uniform sti-en h.. Art low-mctorspeed and a correspon ingly Slow break inthe primary ycircuit, the-ohmic resistance of the coilB-"reduces the current flow" through theprimary winding to a predetermined maXircom.,l 0n thezcontrary, 4in caseoie a higher moterspeed 'with' corresponding quicker breaks in 1 the primary circuit, ther current is reduced owing o increased impedance of the 'coli this'reduc'ing the "chmic `drop in the external resistance and leaving a highervol available for-fthe primarywindings; rogzt e coil.

From the-foregoing description, taken. in connection with the accompanying drawings, the advantages of the construction and the method tif-operation will be readily/apstood that theV apparatus shown is merely illustrative, and that such changes may be made when desired as are within the scope of the claims appended hereto.

Having thus described the invention, what I claim as new is l. A device of the class described comprising a casing, a core therein, primary and secondary windings surrounding the core, a cap for the end of the casing, said cap having a spool-like' projection of non-magnetic material, and a resistance coil'on the projection and connected with thel primary winding.

2. A device of the class described comprising in combination, a casing, a plate of insulating material therein, binding posts on the plate, a core within the casing, primary and secondary windings on the core and connected with the binding posts, a ca attached to the casing and covering the binding posts and having a projecting portion, a resistance coil on the said projecting portion and connected by one of the binding posts in series with the primarywinding, a connection between the primary winding and core, and a binding post connected with the core and extending through the said projecting portion of the cap.

3. A device of the class described comprising a casing, a condenserholder in one end of the casing, an' insulating plate in the other end, a core between the plate and holder, primary and secondary windings on the core, binding posts in the said plate for connection with the terminals of the secondary winding, one terminal ofthe primary winding being connected with one post, a resistance coil connected with the binding post to which the primary winding is connected, the other terminal of the primary winding being connected with the condenser holder, a make and break device connected with the primary winding, and a condenser in said condenser holder in shunt relationto the make and break device.-

4. A device of the class described comprising a casing, a metallic body disposed in one end of the casing, a plate of insulation in the other end of the casing, binding posts in the said plate, a magnetic core in contact with said body, a primary winding on said core having one end connected with one binding post and the other end connected to a switch on the said metallic body, a secondary windin having its terminals connected with the binding posts, a cap applied to the lower end of the casing and having a spool-like portion, a bolt extending through the said spool-like portion of the cap and anchored 1n the said plate in electrical connection with the core, said bolt forming a binding post, and a resistance coil on the projecting portion of the cap and connection with the binding post to which the primary winding is connected.

5. A device of the class described comrising a casing, a metallic condenser holder 1n one end thereof, a core connected with the said holder, a primary winding connected with the said holder, a secondary winding, a resistance coil connected with the primary winding, means connected with the end of the core opposite from the condenser holder in the primary circuit, a make and break device connected with the primary winding, switch means for eonnectin the make and break device in series with t e winding, and a condenser in the said holder di osed in shunt relation to the make and bre device.

In testimony whereof, I aix my signature in the presence of two witnesses.

ERNST EISEMANN.

Witnesses ERNEST ENTENMANN, Fama Kmmnn. 

